Apparatus for grinding twist drills



Dec. 24, 1963 c. 1.. GARRISON 3,114,933

APPARATUS FOR GRINDING TWIST DRILL-S Filed June 27. 1961 6 Sheets-Sheet 1 INVENTOR: ELIFFURD L. EARRISDM.

% A'I'TORNEY j Dec. 24, 1963 c. L. GARRISON 3, 8

APPARATUS FOR GRINDING TWIST DRILLS Filed June 27, 1961 6 Sheets-Sheet 2 I N E M M Z/ N'] CLIPFURD Dec. 24, 1963 c. L. GARRISON APPARATUS FOR GRINDING TWIST DRILLS Fild June 27, 1961 e sheets-sheet :5

INVENTOR. Curran L FARmsuN BY MQ TTORNEY wW B H 6 Sheets-Sheet 4 INVENTOR L'Lrpruzw L. Lmzzzzsun.

EATOAZQRNEY c. L. GARRISON APPARATUS FOR GRINDING TWIST DRILLS Filed June 27. 1961 All, 472

Dec. 24, 1963 c. L. GARRISONI 3,114,988

APPARATUS FOR GRINDING TWIST DRILLS Filed June 27, 1961 6 Sheets-Sheet 5 TIE-1U- Z80) I I l INVENTOR L'LIPPURJJ L. Emrsam 1 E j ja 'onuzv Dec. 24, 1963 c. L. GARRISON 3,

' APPARATUS FOR GRINDING TWIST DRILLS Filed June 27, 1961 6 Sheets-Sheet 6 2 i I ZZZ 2Z5 lNvENToR:

- ELJP URD L. EAHHISUN g: ATTORNEY United States Patent 3,114,988 APPARATUS FUR GRINDING TWIST DRILLS Clifford L. (Garrison, Adrian, Mich, assignor to Oliver Instrument Company, Adrian, Mich, a corporation of Michigan Filed June 27, 1961, Ser. No. 119,955 11 Claims. (Cl. 5155) This invention relates to apparatus for grinding and shaping the cutting edges or lips and relief clearance of twist drills and more especially to a drill grinder or drill grinding apparatus of a character especially adapted for grinding and shaping the cutting edges and relief clearances of medium and large size drills up to three inches or more in diameter.

The medium or small size twist drills used in machine operations are usually fashioned with two flutes or grooves providing two cutting edges or lips. Drills of this character and size may be ground upon apparatus wherein a reversible drill holder is employed in which the drill is mounted and engaged with a rotating grinding wheel while manually oscillating the drill and drill holder to impart relief clearances to the drill point and sharpen the cutting edges or lips. In such apparatus the drill holder is mounted in a support and oscillated with the drill in contact with a rotating wheel to form one cutting lip and relief clearance thereon, the holder then reversed in its support and the other cutting lip and relief clearance formed on the drill.

Drills of medium and larger sizes may be fashioned with two flutes, three flutes or four flutes or spiral grooves depending upon the size of the drill, the larger sizes usually having three or four flutes to promote increased drilling or faster removal of metal.

The present invention relates to apparatus for grinding twist drills particularly for grinding medium and large size drills fashioned with two flutes, three flutes or four flutes, the apparatus being of a character especially adapted for grinding drills of various sizes having different numbers of flutes or spiral grooves.

The invention has for an object the provision of a drill grinding apparatus embodying a grinding Wheel journally supported for continuous rotating in an eccentrically disposed sleeve or quill arranged for rotational and reciprocatory movement to effect an orbital movement of the grinding wheel to grind proper relief clearances or angles upon cutting regions of drills.

Another object of the invention resides in a drill grinding apparatus provided with means cooperating with a rotating and lengthwise reciprocable grinding wheel for simultaneously rotating a drill to be ground, the rotation of the drill being in coordinated or synchronized relation with the reciprocating and orbital movements of the grinding wheel to fashion desired relief angles on a drill.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

FIGURE 1 is a side elevational view of the drill grinding apparatus of the invention;

FIGURE 2 is a top plan view of the apparatus shown in FIGURE 1;

FIGURE 3 is a longitudinal sectional view taken substantially on the line 33 of FIGURE 2 with the drill supporting means removed;

FIGURE 4 is a transverse sectional view taken substantially on the line 4-4 of FIGURE 3;

A amiss Patented Dec. 24, 1963 "ice FIGURE 5 is a rear elevational view of the grinding apparatus shown in FIGURE 1 with the end cover removed;

FIGURE 6 is a detail sectional view of the clutch control means, the view being taken on the line 66 of FIGURE 2;

FIGURE 7 is an end elevational view of a portion of the construction shown in FIGURE 6;

FIGURE 8 is an elevational view of one of the components of the clutch mechanism illustrated in FIG- URE 6;

FIGURE 9 is a fragmentary detail sectional view of the grinding Wheel dressing or truing means, the section being taken substantially on the line 9-9 of FIGURE 2;

FIGURE 10 is a longitudinal sectional view through the drill supporting means, the section being taken substantially on the line 19-10 of FIGURE 2;

FIGURE 11 is a fragmentary sectional view of a locking means for the drill chuck supporting mechanism;

FIGURE 12 is a semidiagrammatic view illustrating a drive control for the drill supporting chuck for adapting the apparatus to grind drill having different numbers of flutes;

FIGURE 13 is a transverse sectional view taken substantially on the line 13-43 of FIGURE 12;

FIGURE 14 is a detail sectional view illustrating a lubricant pumping means for supplying pressure lubrication;

FIGURE 15 is a fragmentary elevational view of the pumping means shown in FIGURE 14;

FIGURE 16 is an end view of a drill provided with four flutes or grooves;

FIGURE 17 is an end view of a drill provided with three grooves or flutes, and

FIGURE 18 is an end elevational view of a drill provided with two flutes or grooves.

The grinding apparatus of the invention illustrated in the drawings is particularly adapted for grinding, sharpening or pointing drills of medium and comparatively large sizes, but it is to be understood that the grinding apparatus may be employed or utilized for grinding or pointing fluted cutting tools genera-11y.

Referring to the drawings in detail and initially to FIGURES 1 through 5, the grinding apparatus or machine is inclusive of a hollow base housing or base frame 10 comprising a lower base or frame section 11 of hollow thin walled construction and an upper frame section 12 supported upon the section 11. The lower base section 11 is formed at its upper region with an inwardly extending flange 14 which mates with a boss portion 16, the sections being secured together by bolts 17 extending through openings in the flange 14 and into threaded openings in the boss portion 16, as particularly shown in FIGURE 3.

The upper section 12, is of generally rectangular shape and is provided with an imperforate web, bottom or floor 18 providing with the vertical walls of section 12 a reservoir or chamber 2%) adapted to contain oil or other suit able lubricant. The grinding wheel, the rotatable drill holding means or chuck and the transmission mechanisms therefor are driven by a motor 22 mounted upon a support 24- contained within the base section 11, the motor being mounted by pivotal means in a conventional manner whereby the weight of the motor 22 exerts tension upon a driving belt 26 engaging a driving pulley 27 mounted upon the motor shaft 28.

The drive belt 26 engages a pulley 32 for driving the grinding wheel supporting shaft, arbor or spindle 34' which supports a grinding wheel 36. The driving belt 26 also engages a driven pulley 46 which operates transmission gearing and other components hereinafter described. The pulley 40 is secured upon a shaft 41 journally supported in bearings contained within a supplemental housing 43 secured to the rear wall of the frame section 12 by means of bolts 44 shown in FIGURES 3, and 14. A removable cover or closure 45 encloses the driving elt 26 and pulleys 27, 32 and 49 as shown in FIGURES 1 and 2.

The grinding wheel supporting shaft 34 is contained within an upwardly extending housing portion 46 formed integral with the upper frame section 12, the portion 46 being provided with a removable cover plate 48 providing access to the interior of the portion 46. In the apparatus of the invention, the grinding wheel 36 and the grinding wheel supporting shaft 34 are mounted so that, in addition to the rotation of the wheel and shaft, they are caused to move in an orbital or eccentric path or locus in order to fashion relief clearance on a drill to be ground.

The housing member 46 in which the grinding wheel shaft 34 is contained is mounted upon a flange portion 50 provided at the upper region of the frame section 12 and is positioned by means of dowel pins 52, shown in FIG- URE 3, and securing bolts (not shown). The housing section 46 is provided with interior bosses 47 and 49 bored to rotatably support a sleeve or quill member 54, the axis of the grinding wheel supporting shaft 34 being eccentric to or spaced sli htly from the axis of the sleeve 54 so that upon rotation of the sleeve 54, the axis of the grinding wheel is caused to move in a circular or orbital path about the axis of the sleeve 54.

It is found that an eccentricity or off-center position of the axis of the grinding wheel shaft 34 with respect to the axis of rotation of the sleeve 54 is approximately one-quarter of an inch to obtain the proper configuration of chisel-type point and relief clearance on the drill to be ground. The grinding wheel supporting shaft 34 is provided at its end regions with tenon portions 60 and 61. The shaft 34 is mounted for rotation on anti-friction bearings 62 and 64, the inner races of which are mounted upon the tenons 6t] and 61. The outer races of the antifriction bearings 62 and 64 are mounted in recesses formed in the sleeve or quill 54 as illustrated in FIG- URE 3.

The quill or sleeve 54, rotatably journaled in the bosses 47 and 49 of the housing 46, is arranged to be reciprocated in order to impart a reciprocating motion to the grinding wheel 36. Keyed to the sleeve 54 by means of feather keys 68 is a sleeve-like member 70 fashioned integrally with a spur gear 72 rotatable with the sleeve 54. Also mounted upon the sleeve 54 is a comparatively short sleeve or bushing 74 which forms a journal bearing for a spur gear '76, the bushing 74 being secured to and rotatable with the spur gear 72.

Disposed in the housing 43 is a shaft 41, driven by the belt 26 through the pulley 40, the shaft 41 being journaled upon ball bearings 81 and 82 as shown in FIGURE 14. Mounted upon the inner end of the shaft 41 is a drive pinion 34 which is in mesh with a gear 86 fixedly mounted upon a countershaft 83, the countershaft being journally supported in ball bearings 90 and 91. The countershaft 88 is supported in a bracket structure 94 in which is mounted the bearing $0, a plate member 95 secured to the member 94 providing a support means for the ball bearing 91.

Also fixed upon a countershaft 88 is a spur gear or pinion 96 which is in mesh with the teeth of the gear 76 journally mounted upon the sleeve or bushing '74 as shown in FIGURE 3. Also mounted upon the sleeve 54 is a cam member 104 which does not rotate With the sleeve 54 but is adjustable about the axis of the sleeve 54 for purposes hereinafter explained.

The left-hand surface 106 as viewed in FIGURE 3, of the cam member 104 is formed with a raised cam surface liiii shown in FIGURE 4 which is in the form of a circular land, a second portion 112 in the form of an annular planar surface spaced from the planar surface of the raised portion or land 108. One extremity of the land 163 is joined with the portion 112 by means of a ramp or tapered region 114 and the other terminus of the land 10?; is joined with the planar surface 112 by a ramp or tapered portion 116.

Secured to the bushing 7d is a cam follower or follower member 118 which engages the cam surfaces of the cam 164. As the cam member 164 is relatively stationary, rotation of the gear 72 and bushing 74, through engagement of the cam follower 118 with the cam surfaces of cam member 104, effects a lengthwise movement of the sleeve 54 and the grinding wheel supporting shaft 34 to form relief clearance upon a drill point D in engagement with the grinding wheel 36.

Means is provided for establishing a controlled driving or clutching engagement of the gear 72 with the gear 76 to drive the sleeve 54, this arrangement being shown in FIGURES 3, 6, 7 and 8. As shown in FIGURE 3, the member fashioned with the gear 72 is formed with a bore slidably accommodating a cylindrically shaped clutch member 120 which is adapted for interlocking or clutching engagement in a recess 122 formed in a side wall of the gear 76.

One end of the bore accommodating the slidable clutch member or dog 120 is closed by means of a cap 124, a spring 126 being disposed between the clutch member 129 and the cap 124 for normally biasing the clutch mem ber toward the gear 76 to engage the clutch member in the recess 122. The clutch member 120 is provided with a notch or recess 128 to accommodate a control pin or plunger member 130, shown in FIGURES 6 and 7.

Referring to FIGURES 6, 7 and 8, the control means for the clutch member 120 is inclusive of a fitting or support member 131 secured to a wall of the housing section 12, the fitting 131 being bored to slidably accornmodate the control pin 13% for the clutch dog or member 12d. Secured to the end of the fitting 131 is a cap 132. Rotatably supported in a bore formed in the cap 132 is a stub shaft 134 provided with a collar 135 fitting in a counterbore or circular recess formed in the cap 132. A control knob or control member 136 is secured upon the shaft 134 by means of a key 137 and u setscrew 138.

The shaft 134 is formed with a tenon 140 which extends into a bore 141 formed in the pin 130, a spring 142 being disposed between the bottom of the bore and the end of the tenon 14-0 for normally biasing the control pin 130 in a righthand direction as viewed in FIGURE 6. The wall of the control pin defining the bore 141 is formed with a pair of diametrically opposed, generally triangularly shaped slots 145, one of which is shown in FIGURE 8. Each of the slots 145 terminates in a kerflike recess or dwell 144. Extending transversely in a bore formed in the tenon 140 is a pin 146 which cooperates with the slots 142.

The control member 139 is provided with a transverse bore in which is press fitted or snugly fitted a pin 150 which is arranged for slidably transverse in slots 152 formed in a portion 153 of the fitting 131 extending into the interior of the housing 12. The cooperative association between the pin 15%) and the slots 152 prevents rotation of the control member 130.

The end of the control member or pin 130 is formed with a generally reetangularly shaped projection or portion 155 defined by parallel Walls 15-5. The projection 155 is formed with an angular or canted surface 158 which is adapted to facilitate engagement of the rectangular projection 155 in the recess or slot 123 formed in the clutch member or dog 120.

The operation of the clutch and control arrangement therefore is as follows: The gear 76 shown in FIGURE 3 is continuously rotated through the gearing hereinbefore described by the pulley 49. The chatch dog 129 is normally held out of engagement with the recess 122 in the gear 7-6 by engagement of the rectangularly shaped portion 155 of the control member 1151) therewith when the latter is extended into the position shown in FIGURE 6. The projection 155 engaging in the recess 1.23 holds the clutch dog 12% in a left-hand direction as viewed in FIGURE 3 out of engagement with the recess 122.

When it is desired to establish rotation of the sleeve 54- in which the grinding wheel supporting shaft is journaled, the operator rotates the control knob 136 which rotates the tenon portion 146i carrying the pin 146. Rotation of the tenon 14% causes the pin 14% to move along the angularly arranged surfaces 143 of the slots 145 to retract the control member or pin 13b in a left-hand direction as viewed in FIGURE 6. During this retractive movement of the pin or plunger 1313, the pin is prevented from relative rotation by engagement of the transverse pin 15% in the longitudinal slots 152 formed in the fitting 131.

Movement of the pin 130 in a left-hand direction, as viewed in FIGURE 6, withdraws the portion 155 out of the recess 12% in the clutch member 12!? and, under the influence of the spring 126, the clutch member is biased or urged toward the gear 76 so that when the recess 122 in the gear '76) moves into registration with the clutch member 12h, the latter is advanced under the pressure of spring 126 into the recess 122, thus establishing a driving connection between the gear 76 and the member 711 car rying the gear 72. Through this arrangement, the sleeve 54 is rotated during the period that the clutch dog or member 126 is engaged in the recess 122.

The cam means 194, which cooperates with the cam follower 118 to effect reciprocation of the sleeve 54-, the grinding wheel shaft 34 and the grinding wheel 36, is adjustable about its axis to vary the phase relation of the reciprocatory movement of the grinding wheel with respect to the rotation of the drill D. Referring particularly to FIGURES 3 and 4, the cam member 164 is provided at its periphery with gear teeth 162. One side wall of housing 46 is provided with a boss portion 164, shown in FIGURE 4-. The other side wall of the housing 4-6 is provided with an opening accommodating a fitting 166, which is secured to the housing by means of screws 167.

A shaft 168 is journaled in a bore formed in the fitting 166 and a tenon portion 176 formed on the rear of the shaft is journaled in a bore formed in the boss portion 164. The intermediate portion of the shaft 1% is formed with a threaded region 172 which is threaded into the interior of a sleeve 1'74. The lower surface region of the sleeve 174- is formed with teeth 1'76 forming a rack portion, the teeth of which are in mesh with the teeth 162 formed on the cam member 1%. Secured upon an end of the shaft 168 is a member 173 provided with a manipulating crank handle 179.

The boss portion 16 and the fitting 166 are provided with aligned bores in which is disposed a rod or member Lit). The sleeve 174 is formed with a bore to receive the rod 1311, this arrangement providing for lengthwise movement of the sleeve with respect to the shaft 168, the sleeve being restrained from rotation by the rod 184). By manipulating the crank 179 to rotate the shaft 168 and the threaded portion 172, the sleeve 17 5 may be adjusted lengthwise of the shaft 163 and, through the enmeshment of the teeth 176 of the sleeve with the teeth 162 of the cam member 1&4, the cam member may be rotatably adjusted about its axis.

Through this arrangement, the relationship of the cam follower 118 to the various components of the cam member M4 provides for an adjustment to establish the proper coordination between the lengthwise movement of the grinding wheel and the sleeve 54 (shown in FIG- URE 3) and the relief region to be formed on the drill D.

Means is provided for indicating to the operator the relative position of the sleeve 1'74 and hence the position of the earn 134. A boss portion 4'7 of the frame member or housing 46 is bored to accommodate a rod or member 134, the latter having a threaded portion 185 6 which is threaded into a threaded portion of the bore in the portion 417, as shown in FIGURE 3. The rod 134 has a tapered extremity terminating in a point 135 which provides an index means.

The upper portion of the sleeve 174 adjacent the index 13-6 is provided with graduations extending lengthwise of the sleeve arranged for cooperation with the index 186 forindicating to the operator the relative position of the sleeve 174 and the cam member 1%. The upper portion of the cover plate 4-3 is provided with an opening in which is mounted a transparent member 138 such as a plate of glass through which the index 1336 and cooperating graduations may be viewed by the operator.

The abrasive section of the grinding wheel is cup shaped and is mounted upon a backing plate 1%, shown in FIG- URE 3, which is supported upon a hub portion formed on a disc-like member 1%, the latter being keyed on the tenon portion 66 of the shaft 34 by a key 193. The backing plate 1% of the grinding wheel construction is secured to the member 192 by screws 191 and the member 192 is secured on the tenon portion of shaft 34 by means of a collar 194 threaded upon the threaded end portion of the tenon.

Means is provided for biasing or urging the sleeve 54 in a right-hand direction as viewed in FIGURE 3 to maintain the cam follower 118 at all times in engagement with the surface of cam 11%. With particular reference to FIGURE 3, the boss portion d9 of the housing member an is bored to slidably accommodate a sleeve 1%. Fitted into the righthand end of the sleeve 1% is an abutment member Ztlti having a head portion Ztll which bears against a side face of the member 7t? fashioned with the gear '72.

Secured to the boss portion 49 is a plate 292 which forms an abutment for an expansive coil spring 2114 con tained within the sleeve 1%, the spring being arranged to bias the abutment 2% toward the gear member 70. Through this arrangement, the expansive force of the spring 204 at all times urges the cam follower 118 into engagement with the cam surface region of the cam member 104. A cup-like member 2% has its flange portion surrounding and in engagement with a sealing ring 208, sutficient space being provided between the end of the flange of the member 296 and the plate 2492 to facilitate lengthwise movement of the sleeve 54 and the grinding wheel construction.

A second cup-like member 212 is arranged at the opposite end of the shaft 34 adjacent the pulley 32 and embraces a sealing ring or gasket 214 with suiiicient space provided for lengthwise movement of the cup-shaped member 212 to accommodate the lengthwise movement of the sleeve 54. Suitable lubricant seals or sealing rings 215 and 218 are provided adjacent the end regions of the sleeve 54 as shown in FIGURE 3.

The journal regions or bearing surfaces for the sleeve 5 are lubricated through suitable circumferential lubricating grooves 229 and 221, the grooves 221 and 221 being in communication with lubricant conveying tubes 222 and 223, the tubes being connected with a lubricant pumping means hereinafter described.

The drill D to be ground is supported by a chuck 230, shown in FIGURES 1, 2 and 10, which is adapted to be rotated, the chuck being angularly adjustable to vary the angle formed on the end of the drill or drill point. The chuck 23b is equipped with drill engaging and supporting jaws 231 which are adjustable radially by means (not shown) to receive and support drills of various sizes. The housing 233 of the drill chuck construction 2319 is secured to a plate 234 formed with a hub portion 235.

Surrounding the hub portion is a stationary housing 236 in which is mounted roller bearings 233 and 239, as shown in FIGURE 10, the hub portion 235 of the chuck construction being journally supported in the bearings 23% and 233. The inner race of the roller bearing 23% is secured in position by means of an end plate 246'. A

7 metal ring 24-2 surrounds the plate 24d and is secured to the housing 236. A lubricant sealing member is contained within a peripheral recess formed in the plate he housing 236 is formed with diametrically disposed laterally extending boss portions which support rods or members 248 as shown in FiGURES l and 2.

Slidably mounted upon the rods 43 is a member 253 formed at its central region with a boss 252 provided with a bore in which is slidably received a pin 254 having a tapered or pointed extremity 255' adapted to enter a conically shaped opening 256 formed in the shank end of a drill in order to stabilize and center the drill. Extending upwardly from the boss portion 252 is a boss which is bored and threaded to accommodate a threaded member 269 which provides a locking means for locking the drill engaging pin 254 in ad usted position in the boss 252.

The member 250 is slidably adjustable lengthwise of the rods 243 and is arranged to be locked in adjusted position. One of the boss portions which is bored to accommodate one of the rods 248 is prodded with a slot or a split region 262, shown in FIGURE 1, and the adjacent boss portion formed with a second boss 26 which is bored to accommodate a locking member 266 provided with a handle portion 26 The locking member 266 extends across or bridges the split region 262 and is threaded into a threaded bore in one portion of the adjacent boss so that the boss may be drawn into clamping engagement with the adjacent rod 243. Through adjustment of member 2558, drills of various lengths may be accommodated The drill supporting chuck is driven by a suitable means hereinafter described. The housing 236 is adjustable about a vertical axis in the plane of the face of the grinding wheel 36 in order to vary the angularity of the axis of the drill and hence the angularity or taper of the cutting lips or edges on the drill point. The housing 236 is sup ported upon a hollow member 27th, the latter being rotatable about the axis of a vertical shaft 272, shown in FIG- URE 10, the shaft forming a component of the arrangemerit for rotating the drill supporting chuck 239.

The housing 236 is secured to the member 276) by securing bolts (not shown). The member 279 is formed with fiat surface portions 271 which are in a common horizontal plane and which engage and are slidable upon a horizontal raised surface or land 274 formed upon a member 276. The member 276 is supported by an intermediate frame member 273 which is supported upon the section 12 of the main frame construction. Formed in a lower wall portion of the member 270 is an arcuately shaped T-slot 250 which accommodates or receives a head 282 of a threaded member 283, as shown in FIGURES 10 and ll.

The member 27 6 is formed with a vertical bore in which is slidably disposed a plunger 285, the latter being provided with a bore having a threaded portion to accommodate the threaded portion of member 283. Formed in the plunger 235 is a transverse bore 257. Extending into the bore 287 is a tenon 2&9 formed on a manipulating rod or shaft 290, the tenon 239 being eccentric with respect to the axis of the shaft or rod 299 as shown in FIGURES l0 and 11.

Extending transversely through a bore in the end region of the shaft 296 is a pin 292 which forms a hand grip portion for rotating the shaft 2%. The portion of tie member 276 adjacent the shaft 2% is provided with a threaded opening accommodating a screw 294 the extremity of which extends into a peripheral groove 295 formed in the circumference of the shaft 299 to retain the shaft 2% in the bore in member 276 but permitting rotation of the shaft. The shaft 2% and the eccentric tenon 289 cooperate with the plunger 2555 and the headed memher 283 to provide a locking means for quickly securing the member 279, the housing 236 and the chuck construction 236 carried thereby in a desired angular position.

From FIGURE 11 it will be seen that rotation of the shaft in one direction engages the eccentric tcnon 28? with 8 a surface of the bore 237 to move the plunger downwardly bringing the head 282. into frictional clamping engagement with the member 270 to effect a locking of the platform or member 2'76 to secure the chuck 23% in a desired angular position. Rotation of the shaft 2%) in an opposite direction releases the locking means.

Suitable graduations may be inscribed on the surface 274 cooperating with an index for indicating the angularity of the axis of the chuck with respect to the longitudinal axis of the grinding machine. The member 276 and the drill supporting chuck and associated components are arranged for adjustment in a direction axially of the grinding wheel.

As shown in FIGURE 11, there is secured to the member 2573 a member 293 formed with convcrgently arranged surfaces 2 9 and providing ways to accommodate slida le movement of the member 276 and components carried thereby in a direction longitudinally of the machine. A gib 301, shown in FIGURE 11, is provided for adjustment to eliminate lost motion between the ways provided by the surfaces 299 and 399 and the member 276.

Secured to the member 278 is an element or block 3%, shown in FIGURES l and 3, having a threaded bore to receive a threaded portion or lead screw portion 3G5 of a shaft 3%. Secured to the forward end of member 276 is a fitting 398 in which the shaft 3496 is journaled for rotation. The portion of the shaft extending beyond the fitting 398 is equipped with a hand wheel 310 having a manipulating handle 311 for rotating the hand wheel and the shaft 366. An anti-friction or ball bearing 314 provides a thrust bearing means engaging a collar 315 on the shaft 366.

By rotating the hand wheel 310 and the shaft 306,

the lead screw portion 395 being threaded in the block 363, longitudinal movement of the member 276 and components carried thereby is effected relative to the portion 278 of the grinding machine frame construction. As the member 276 carries the member 276 and the drill mounting chuck 233, the adjustment through manipulation of the hand wheel 31!) adjusts the chuck 230 toward or away from the grinding wheel to facilitate the establishment of the proper relation between the point of the drill D and the grinding wheel. In grinding fluted drills, the drill supporting or mounting chuck 23!} is rotated in predetermined relation with respect to the cycle of eccentric or orbital movement of the grinding wheel which ensues through the rotation of the sleeve 54 supporting the grinding wheel shaft and the grinding wheel in order to grind the relief clearance adaccnt each of the cutting edges of the drill. The apparatus of the invention includes means for readily changing the speed of the drill chuck dependent upon the number of cutting edges or lips on the drill to be ground.

The arrangement includes power transmission means for rotating the chuck 239 at three different speeds to accommodate drills having two flutes, three flutes or four flutes. With particular reference to FIGURE 3, it will be apparent that the construction includes a countcrshaft 318 which is journaled in anti-friction or ball bearings 319 mounted in bosses 32a)- carried upon a backing plate 322 shown in FIGURES 2 and 5, the backing plate being secured to the frame of the machine.

Fixedly secured to one end region of the countershnft 318 is a gear 324, and fixedly secured on the opposite end region of the shaft 318 is a gear 326. Also mounted upon the shaft 318, intermediate the boss portions 32; is a third gear 323. The gears 324, 325 and 328 are ke ed to the shaft 313 so as to rotate therewith. The backing plate 322 is also formed with bosses 329 and 339, shown in FIGURE 3, each supporting an anti-friction or ball bearing 331. Disposed between the bearings 331 is a sleeve 332 having tenon portions journally supported in the bearings 331 for rotation relative to the bosses 329 and 330.

Fixedly secured upon the sleeve and arranged to rotate therewith are three gears designated respectively 334, 336 and 338 forming a gear cluster as shown in FIGURE 3. The gears 334-, 336 and 338 are secured together in cluster formation by means of bolts 339, the gear unit or gear cluster being slidable lengthwise of the sleeve 332. A bar or key is secured in a longitudinally extending groove formed in the surface of the sleeve 332 and the gears of the cluster are provided with recesses accommodating the bar or key 34% whereby rotation of the gears effects rotation of the sleeve 332.

Extending through the interior of the sleeve 332 is a shaft 342. Mounted upon the right-hand end region of the shaft 342, as viewed in FIGURE 3, is a sleeve 344 having an interlocking tongue and grOOVe connection 34-5 with one end of the sleeve 332 which carries the gear cluster comprising gears 334, 336 and 33?. A driving connection is established between the sleeve 344 and the shaft 342 by a pin 348. The right-hand end of the shaft 342 as viewed in FIGURE 3 is formed with a tenon 35% mounted in an anti-friction or ball thrust bearing assembly 352, the latter being held in position by means of a cap 354 secured to an end wall of the frame 12. The pin 34% is formed of soft metal providing a shear or safety pin to prevent damage in the event that an abnormal condition occurs in the operation of the mechanism.

Depending from a member 379 is a hollow boss 3 5s in which is mounted anti-friction or ball bearings 353 shown in FIGURES 3 and 10. Journaled in the ball bearings 358 is a sleeve-like member 360 formed at one end with a bevel gear 362. The shaft 34-2 is formed with a longitudinally extending groove, recess or kcyway 36d and the interior of the sleeve 36% formed with a recess, the recesses in the sleeve 36% and shaft 364 accommodating a feather key 366 which is secured to the sleeve 369 by means of a ring 367 so that the key see is slidable with the sleeve 369 relative to the shaft 342.

Through the provision of the key 366, a driving connection is at all times established between the shaft 342 and the bevel gear 362 irrespective of the lengthwise adjusted position of the gear 362 with respect to the shaft. As the boss portion 356 is movable with the member 370 and as the latter is secured to the member 276 by volts 369, one of which is shown in FIGURE 3, the bevel gear 362 is movable with the member 276 when the hand wheel 3149 is rotated.

The member 37h is provided with a hollow portion in which is mounted ball bearings 372 and 373. Journaled in the bearings 372 and 373 is the vertically disposed shaft 272, a bevel gear 374 secured to the lower end of the shaft 272 being in mesh with the teeth of the bevel gear 362. Fixedly secured to the upper end of the shaft 272 is a bevel gear 376.

With particular reference to FIGURE it will be seen that the member 270 has a hollow interior region in which is disposed a horizontal shaft 378 on which is fixedly secured a gear 38% in mesh with the gear 376 mounted on shaft 272. Secured to the right-hand end of the member 27%} as viewed in FIGURE 10 is a fitting 332 in which is mounted an anti-friction or ball bearing 334.

The end of the shaft 37$ is provided with a tenon 386 which is journaled in the anti-friction bearing 384. The member 279 is formed with a boss portion 388 which is bored to accommodate a ball bearing 3%. The left end region of shaft 378 as viewed in FIGURE 10 is formed with a tenon portion 3% which is journally supported in the ball bearing 3%. A sleeve 3% extending into the bore in the boss 388 forms a positioning means for the bearing 8%, the sleeve 394 being restrained against endwise movement by a plate 3% secured to the member 27%.

Means is provided associated with [the member 279 for maintaining the latter in assembled relation with the member 37%. As particularly shown in FIGURES 3 and 10, the fitting 382 is formed with an extension 414 and the wheel guard 464 of the machine formed with a boss 415. The boss 415 is bored to accommodate a plunger 416 formed with a tenon portion 417 surrounded by an expansive coil spring 413. The expansive pressure of the spring 418 biases the plunger 416 downwardly upon the fitting 414- to maintain the member 279 in engagement with the member 370*.

The member 370 is formed With an upwardly extending circular projection 371 extending into a circular opening in a boss portion 375 of the member 270, the circular projection 371 forming a journal about which the member 27% is adjusted to vary the angular position of the axis of the drill supporting chuck 23%. The downward pressure exerted by the spring-loaded plunger 41o upon the fitting 414 maintains the boss portion 375 of member 27% in proper relation with the circular projection 371.

As shown in FIGURE 10, the housing 236 is bored to accommodate a shaft 400 upon which is journally supported a spur gear 4 32. Fixedly secured upon the shaft 378 to rotate therewith is a drive gear or pinion 404 which is in mesh with the gear Mounted upon the hub portion 235 of the plate 234 mounting the driil supporting chuck 239 is a gear 496 which is in mesh with the gear 462. The gear 4% is secured to the hub 2353 by means of a key 4% and a setscrew 41% shown in FIGURE 10.

Rotation of the shaft 342 is transmitted through the gears 36?. and 374 to the shaft 272 and through the gears 3'76 and to the shaft 373. The pinion 4M, rotating with the shaft 373, transmits rotation through the intermediate pinion or gear MP2 to the gear 4% to rotate the drill supporting chuck 23%. Means is provided for shifting the cluster of gears 334, 336 and 338 relative to the gears 324, 32 6 and 323 to establish selectively three different speeds for the drill chuck 23% in order to grind the lips on drills having two, three or four flutes.

The means for effecting the shifting of the gear cluster is illustrated in FIGURES 1, 5, 12 and 13. Mounted upon the front wall of the frame portion 12 of the grinding apparatus is an indexing plate 424 held in place by screws 425. Secured to the plate 42 by screws are is a fitting 428 extending into the interior of the frame portion 12. The portion 42-3 is provided with spaced arms or pontions 43%, shown in FIGURES 12 and 13,

the arms supporting an elongated member 432 secured to the arms by screws 433.

The member 432 is formed with convergently arranged surfaces 435 providing a dovetail-shape cross section as shown in FIGURE 5. Slidably mounted upon the elongated member 432 is a carriage 436 to which is secured a toothed member or rack bar The plate 424 and the fitting 423 are formed with bores within which is rotatably supported a shaft .40 upon the inner end of which is secured a pinion 442, the teeth of the pinion being in mesh with the teeth of the rack bar 438, as shown in FIGURES 5 and 13.

The carriage member ass is formed with projections 446 shown in FIGURE 12, which straddle the peripheral region of the central gear 338 of the gear cluster. Thus, movement of the carriage 436 along the ways provided by the member 432 will cause corresponding movement of the gear cluster along the supporting sleeve Means is provided accessible exteriorly of the housing portion 12 for shifting the carriage 436 to shift the gear cluster. Keyed or otherwise fixedly secured to an end portion of the shaft 44s is an arm provided with a boss portion 451 bored to accommodate an indexing pin 452, the latter being provided with a manipulating knob 453.

The pin 452 is provided with a collar 454. An expansive coil spring 455, contained in the bore in the boss portion 451, urges or biases the pin 452 toward the plate 424. The end of the pin 452 is provided with a tenon 4-56 which is adapted for selective engage rent with a plurality of openings 458 formed in the plate 424, the openings being arranged in an arcuate pattern about the axis of thes shaft as a center. By moving the pin 452 by manipulation of the knob 453, the tenon ass may be disengaged from one of the openings 453, and the arm 450 rotated to bring the tenon 456 into registration with another of the openings 458.

There are five positions of the arm 45d and hence five corresponding positions of the gears 334, 335 and 338 of the gear cluster. In the position of the arm shown in FIGURES 1 and 12, the gear 333 is in mesh with the driving gear 328. When the arm 450 is moved to an extreme left-hand position, as viewed in FEGURE l, the gear 334. is in mesh with the gear 324, and, when the arm 450 is moved to the extreme right'hand position, as viewed in FIGURE 1, the gear 336 is in mesh with the gear 326.

When the arm is moved to an intermediate position between no right and loft-hand extreme ositions and the center position, the gears are in neutral, that is, none of the gears of the gear cluster is in mesh with any of the drive gears 324, 32 6 or 32%. Through this arrangement, three different predetermined speeds of rotation may be imparted to the drill supporting chuck 239, the particular speed being dependent upon the number of flutes in the drill to be ground.

Where the drill being ground is fashioned with two flutes and has two cutting edges, the gears 324 and 33- are enmeshed. Where the drill being ground has three flutes, viz. three cutting edges. the gears ass and 312.6 enmeshed. Where the drill being ground has four flutes viz. four cutting edges, the gears 32% and 338 are enmeshed. Through this arrangement, the operator shifts the position of the arm 450 to accommodate the speed of the chuck 230 to a drill having two, three or four flutes.

Means is provided for dressing the grinding wheel 36, such means being shown in FIGURES 2 and 9 and is supported by a wheel guard or shield 464. The guard is mounted upon the movable member 276 and surrounds or embraces a major portion of the grinding wheel except the region of the wheel engagable with the drill D. A tube 466 is connected with a nozzle inside of the shroud 464, the tube being connected with a supply of coolant, such as water, which is directed onto the grinding wheel for cooling the Wilt-:61 and the drill being ground.

Secured to the wheel guard is a frontal plate 468 formed with a boss portion 470 as particularly shown in FlGURES 2 and 9. The boss portion 470 and a boss portion of the guard 454 are provided with aligned bores in which a shaft 472 is rotatably supported, the shaft being provided with a manipulating handle 474. Mounted upon the shaft 4-72 is an arm 476 secured to the shaft by a key 4 77, the arm being disposed between the fa e of the grinding wheel 36 and the plate 463 as shown in HGURE 9.

Mounted in the arm 475 is a member 479 equip ed with a wheel truing diamond or tool 489, the member 479 being removably secured to the arm by a setscrcw The arm is provided with a drill gage plate 4-32 which is adapted to be swung across the face of the grinding wheel and to be engaged by the drill to properly position the drill lengthwise in the chuck. The plate is provided with an angular edge or end (not shown). The drill supporting chuck 23@ is rotated by hand, with the gear transmission mechanism in neutral position, to bring a cutting lip of the drill into parallel relation with the angular edge or end region of the plate. This determines the proper position of the drill preparatory to inita' g grinding operations. As the wheel truing arrangement shown in FIGURE 9 is supported by the member 276, rotation of the hand wheel 3MB is effective to move the member 276 lengthwise of the grinding machine and simultaneously move the plate 463 carrying the grinding wheel truing device toward or away from the grinding wheel.

When it is desired to dress the grinding wheel, the hand wheel 319 is rotated until the truing diamond 480 is a position whereby the swinging of the arm 4-76 by manipulation of the handle 4-74 brings the diamond 430 into contact with the face of the grinding wheel 36. After the wheel is dressed or trued, the handle 474 is moved in a direction to swing the arm 476 and the truing diamond 43% out of engagement with the grinding wheel to permit drill grinding operations to be carried on. The drill grinding apparatus of the invention is inclusive of pumping means for supplying lubricant under pressure to various bearings of rotating components of the apparatus, the pumping means being illustrated in EEG- URES 5, 14 and 15. As shown in FIGURE 14, the countershaft 88, which is driven by the pinion 84 rotated by the pulley 49, is equipped with an eccentric or cam 45 0. The countershaft supporting means 94 is fashioned with a boss portion 492 and the rear wall of the frame portion 12 is formed with bosses 493 and 494. The boss 4'92 is bored to accommodate a rod or member 4%, the upper end of which is fashioned with a bifurcated member 497 journally supporting a roller or cam follower 4-93, the latter being in engagement with the eccentric or cam 49%. Upon rotation of the countershaft 33, the eccentric or cam 49% through its engagement with the roller 4%, eifects vertical movement of the rod or member 496.

The bosses 493 and 494 are formed with aligned bores to slidably accommodate a rod or member Still, the upper end of which is adapted to abut the lower end of the push rod 4 Mounted on the push rod or member Silt) at a region intermediate the bosses 493 and 4 94 is a collar 592 which is positioned on the rod by means of a pin 593. An expansive coil spring 591 is disposed between the collar 562 and the boss 4 for biasing or urging the rod Silt) upwardly as viewed in FIGURE 14.

A pump assembly 504 is disposed so as to be operated by vertical reciprocation of the push rod 5% under the influence of the eccentric or cam 499. The pump assembly 5534 is carried by a mounting plate 5% secured by screws to a wall of the frame member 12 of the apparatus. The pump assembly includes a casing 56% provided with a plurality of chambers to accommodate a corresponding number of pumping plungers or members.

In the embodiment illustrated the pump casing 588 is fashioned with three bores or chambers adapted to accommodate three pumping plungers 510, 511 and 512. Each of the pump plungers is individual and all of the plungers are actuated by a crosshead 514. The lower end of the rod 539 is secured to the crosshead 514 by means of a pin 515, as shown in FIGURES 14 and 15.

Disposed beneath each of the plungers 5E0, 511 and 512 is an expansive coil spring 513, the springs nesting in bores formed in the lower regions of the pump plungers normally biasing the pump plungcrs upwardly in contact with the cross-head 514 as viewed in FIGURES 14 and 15. Arranged in parallelism with the bores accommodating the pump plungers are three bores, each of the second series of bores accommodating inlet and outlet checl; valve means for one of the pumping plungers. One of the check valve arrangements is illustrated in FIGURE 14.

Disposed so as to establish communication between a bore containing a pump plunger and its adjacent bore containing the valve means is a communicating passage 52-7, each of the passages 520 being closed at its outer end by means of a plug 522. Disposed in each of the bores adjacent the pump bores is a valve cage 524. Each of the bores containing a valve means is formed with an inlet 526 which opens into a reservoir containing a quantity of liquid lubricant, the bottom or floor of the reservoir being the frame member 13.

A supply of liquid lubricant 528 is contained in the reservoir, provided by the floor It; and the side and end walls of the frame portion 12, the lubricant being ad mitted through the inlet passages 526 in the pump assembly 594. Each valve cage 524 is provided with an inlet check valve preferably in the form of a ball 530 and an outlet check ball valve 532. Each of the bores containing a valve assembly is provided with an outlet fitting S34.

Gne of the fittings 534 is connected with the flexible tube 223 for conveying lubricant to a groove 5353 sur rounding one end region of the sleeve 54 shown in FIG- URE 1. The intermediate fitting 534 of the pump as sembly is connected with a tube 222, the latter being in communication with a groove 54% in the frame structure surrounding the other end region of the sleeve 54 to lubricate the journal means at this region of the sleeve.

The third fitting 534 is connected by means of a flexible tube 544 with a fitting 545, shown in FIGURE 3, which is in communication with a lubricant conveying channel 35 in the member 379 for conveying lubricant under pressure to the chamber 550 surrounding the vertically arranged shaft 272, the lubricant being forced upwardly through the bearings 373 to the interior of the member 279 for lubricating the gearing and components disposed interiorly of the member 2719. Through the pumping arrangement above described, lubricant under pressure is delivered to the components of the apparatus requiring pressure lubrication.

The grinder of the invention may be employed as a dry grinder or for larger drills, water may be supplied to the grinding wheel and the work through the tube 455 connected with the wheel guard 464. The portion 73 of the frame of the apparatus is provided with an outwardly extending tray portion 558 bounded by an upwardly extending flange 563 which forms a basin to receive the water or other coolant after its delivery onto the grinding wheel. The water may be drained away from the basin or recirculated by pumping means (not shown). A bafile plate 562 is secured to an end of the member 276 to divert water thrown from the grinding wheel into the basin provided by the tray 558.

A typical drill grinding or sharpening operation of the grinding apparatus of the invention is as follows: As sume that a drill D of the character illustrated in FIG- URE 16 having four flutes, the cutting edges 570 and the relief or clearance surfaces 572 of which are to be ground, is inserted in the drill supporting chuck 239. The arm 476 is then swung into drill gaging position and the drill adjusted lengthwise of its cutting and engaging a surface of the gage plate 482. The drill is then clamped in the mounting chuck 23%. With the transmission gearing in neutral position, the operator rotates the drill mounting chuck by hand to bring a cutting lip of the drill into parallel relation with the angular end or edge of the gage plate 482. The drill is then in an initial position to initiate a grinding operation so that the operations of the mechanism function in proper sequence. The drill centering and stabilizing pin 2% shown in FIGURE is then adjusted into engagement with the shank end of the drill and is held in adjusted position by manipulation of the clamping screw 26%. The chuck 230 and its supporting construction is then adjusted in an angular direction in an arcuate path about the axis of the vertically arranged shaft 272 as a center and is clamped in adjusted position by manipulation of the handle 292 to draw up the locking member 282 shown in FIGURE 11. The motor 22 is energized by manipulation of the starting button 582 of a control switch unit 584. The grinding wheel is dressed by manipulation of the arm 476, shown in FIGURE 9, equipped with the dressing diamond 480, the arm being oscillated to move the dressing diamond across the face of the wheel by manipulation of the handle 474 as the hand wheel 310 is rotated to advance the arm 476 toward the grinding wheel 36. After the wheel is dressed the handle 474 is moved to a position to shift the arm 4-76 and the dressing diamond 480 away from the grinding wheel. The grinding wheel is dressed or trued before the clutch means, shown in FIGURE 6, is brought into operation so that the grinding wheel rotates without longitudinal reciprocation during the wheel dressing operation.

The energization of the motor 22, shown in FIGURE 1, through the medium of the belt 26 and the pulleys 32 and All, causes rotation of the grinding wheel shaft 34, the grinding wheel 36, reciprocation of the lubricant pumping pistons Sill, 511 and 512 shown in FIGURES 14 and 15, and rotation of the gear '76.

The operator then manipulates the handle 179 of the cam adjusting arrangement, shown in FIGURE 4, rotating the threaded member 1'72 to adjust the cam structure 104 through the enmeshment of the teeth 152 on the cam construction with the teeth 176 of the rack formed on the member 174. This adjustment brings the inside edge of the cup-shaped grinding wheel in proper relation with the extreme point of the drill so that when the clutch construction shown in FIGURE 6 is manipulated to establish reciprocatory movement of the grinding wheel through lengthwise movement of the sleeve 54, a proper relation is established for grinding the relief surfaces 572 on the point of the drill.

The transmission control arm 45% is then moved to the central position as viewed in FIGURE 1, which movement positions the gear cluster shown in FIGURE 3 lengthwise of the supporting sleeve 332 to establish enmeshment of the gear 333 with the gear 328. The enmeshment of the gear 33-8 with the gear establishes the proper correlation between the rotative speed of the drill supporting chuck 23d and the reciprocatory movement of the sleeve 54-, and the orbital movement of the grinding wheel supporting shaft 34 and the grinding wheel 36 to grind the relief surfaces 572 on the drill D having four flutes. The operator then rotates the clutch actuating knob 1%, shown in FIGURES 5 and 6, which movement withdraws the pin 136 from engagement with the clutch member 1%, shown in FIGURE 1. The clutch member 1261, being under the influence of the spring 12:6, is urged toward the gear 76 and, when the recess 22 in the continuously rotating gear 7-5 is in registration with the clutch member 126, the latter moves into the recess and establishes a drive connection with the gear '72 to rotate the sleeve 54. During rotation of the sleeve 54 it is reciprocated under the influence of the cam surfaces on the cam member We to reciprocate the grinding wheel 36 to grind the relief surfaces 572 on the drill point. As the axis of rotation of the grinding Wheel is eccentric with respect to the axis of rotation of the sleeve rotation of the sleeve 5 causes the grinding wheel to move in an orbital path in addition to the individual high speed rotation of the grinding wheel and its reciprocation under the influence of the cam means 164-. Through this arrangement the drill is being rotated by the supporting chuck 23ft in coordinated relation with the rotation of the grinding wheel, its orbital movement and its reciprocat-ory movement to properly shape or grind the relief surfaces 572, which actions effects a sharpening of the cutting edges or lips 57%) on the drill point. During the grinding operation, the operator, through the manipulation of the hand whee. shown in FIGURES 1, 2 and 3, advances the drill chuck and drill toward the grinding wheel until the drill point has been ground to he extent desired. The operator then rotates the clutch control knob tee in the opposite direction, releasing the in 1 33 for movement, under the influence of spring 14 2, in a right-hand direction as viewed in FIGURE 6 to engage in the slot or recess 128 formed in the clutch member 12%? and thereby effect withdrawal of the clutch member 123* from the recess 122 in the gear 76 to stop rotation of the drill supporting chuck 236', the drill D, and the sleeve 54. The chuck jaws 231 of the chuck motions of the grinding wheel 36 will or shape the three relief or clearance surfaces cutting lips on the drill of the character s own in FES- aud ll.

sin in F; n c

he transrni on is to be grounded, the oper control handle @52 to the re ie 1'. viewed in FIGURE 1 which shifts the trated in FlGURES l2 and 13 to posit .gear 336 into enmeshment with the action estab ishes a transmission drive and position as cluster illusto bring the This " 6 and URE 17.

When a drill having two flutes is to be apparatus, the operator shifts the co l ha: the extreme left-hand position, as sho' which operatic-n the teeth of gear M teeth of gear "24 to establish the proper {C of the drill and drill supper chucl; so l1 tion is coordinated with the compel and u'eciprocatory movements of the grinding wl' to grind two relief surfaces on the drill D illus in FIGURE 18.

It will be apparent that the apparatus of the invention is readily adapted to grind drills of the so-called larger sizes having two, three or four fiutes by manipulation of the transmission control handle or means or angularity of the cutting edges or": the drill may be varied by changing the angular position of the drill chucl; and supporting structure shown in FlGUREL l, 2, lb The apparatus is adaptable for grinding drills of various kinds and sizes without the use of attachments through the adjustments and control means hereinbefore described.

it is apparent that within the scope of the invention, modifications and erent arrangements may be made other than as herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. Apparatus for grinding fluted twist drills, bination, a support, a sleeve mounted on said arranged for rotational and rcciprocatory movements elative to the support, a grinding wheel, a supporting shaft for the grinding wheel is also upon the sleeve dior orbital movement about the of rotation of the sleeve, means for rotating the grindi. wheel and its sup porting shaft, a first gear journall on said at such iotaitional, orbital s y mounted sleeve, a second gear arranged to be rotated with said sleeve, rotatable means for mounting a drill to be ground, means associated with said second gear for establishing a drive connection with the rotatable drill mounting means, clutch means for establishing a drive connection between said first and second game, cam means asso ated with said sleeve and said second gear for eff 'eciprocatory movements of said sleeve and grinding wheel when said clutch means estaolishes a drive connection between said :rst and second gears, rack and gear means for adjusting the relative position of said cam .means, and speed changing gearing for establishing predetermined diilerential speeds of the drill mounting means dependent upon the number of flutes in the drill to be ground.

2. Apparatus for grinding twist drills, in combination, a support, a sleeve mounted on said support arranged for rotational and reciprocatory movements relative to the support, a grinding wheel, a supporting shaft for the grinding wheel journaled upon the sleeve for orbital movement about the axis of rotation of the sleeve, means for rotating the grinding wheel and its supporting shaft independently of the rotation of said sleeve, a gear journally mounted on said sleeve, a second gear arranged to be rota w said v rotatable means for mounting a drill to be ground, means associated with second gear for establishing a drive connection with the rotatable drill mounting means, manually controlled clutch 1.121113 for establishing a drive connection between said first and second gears, cam means associated with said sleeve and said second gear for effecting reciprocatory movements of said sleeve and grinding wh cl when said clutch means establishes a drive connection between said first and second gears, speed changing gearing including a counteriaft, a plurality of gears mounted on and rotatable with t countershaft, said countershaft arranged to be rotated by said second gear, a gear cluster movable to selected positions and cooperable with the gears on the countershaft for establishing predetermined differential speeds of the drill mounting means, and rack and pinion means for manually snn ng the gear cluster.

5. Apparatus for grinding fluted twist drills, in combination, a support, a sleeve mounted on said support arranged for rotational and reciprocatory movements relative to the support, a grinding wheel, a supporting shaft for the grinding wheel journalcd upon the sleeve for orbital movement about the axis of rotation of the sleeve, means for rotating the grinding wheel and its supporting shaft independently of the rotation of said sleeve, :1 gear journally mounted on said sleeve, 21 second gear arranged to be rotated with said sleeve, rotatable means for mounting a drill to be ground, means associated with said second gear for establishing a drive connection with the rotatable drill mounting means, manually controlled clutch means for establishing a drive connection between said first and second gears, cam means associated with said sleeve and said second gear for effecting reciprocatory movements of said sleeve and grinding wheel when said clutch means establishes a drive connection between d first and second gears, speed changing gearing including a countershaft, a plurality of gears mounted on and rotatable with the countershaft, said countcrshaft arranged to be rotated by said second gear, a gear cluster movable to selected oositions and cooperable with the gears on the countershaft for establishing predetermined clirlerential speeds of the drill mounting means, means for lubricating journals of the rotatable sleeve and drive mechanism for the drill mounting means including a lubricant pump having a plurality of pump pistons, cam driven means for actuating said pump pistons, and a lubricant reservoir for said pump arranged to collect lubricant from the journals for recirculation by the pump.

4. Apparatus for grinding twist drills, in combination, a support, a hollow member journally mounted by the support, a grinding wheel, a shaft arranged to support the grinding wheel, said shalt extending within the hollow me nber and journaled for rotation about an axis moving in an orbital path about the axis of rotation of the hollow member, means for mounting a drill to be ground, sai drill mounting means being arran ed for rotation, an electrically energizablc motor, power transmission mechanism adapted to be driven by said motor, means for driving the grinding wheel supporting shaft from said motor, cam means, an element controlled by the cam means adapted to effect reciprocatory movement of the hollow member and the shaft supporting the grinding whee], clutch means arranged between the power transmission mechanism and said cam controlled element for establishing a drive for rotating the drill mounting means through said cam controlled element, and rack and pinion means for adjusting said cam means to change the phase relation between the reciprocatory movement and orbital movement of the grinding wheel.

5. Apparatus for grinding twist drills in combination, a support, a rotatable sleeve journaled on the support, an abrasive wheel, a shaft journaled for rotation on the sleeve and mounting the abrasive wheel, the axis of rotation of the abrasive wheel being eccentric with respect to the axis of rotation of the sleeve whereby the axis of the wheel moves in an orbital path, cam means for reciprocating the abrasive wheel lengthwise of its axis of rotation, supporting means for a drill to be ground, means synchronized with the reciprocatory and orbital movements of the abrasive wheel for rotating the drill supporting means to grind relief regions on the drill, adjusting means for said cam means including a second rotatable shaft, and gearing operated by rotation of said second shaft for adjusting said earn means.

6. Apparatus for grinding twist drills in combination, a support, a rotatable sleeve journaled on the support, an abrasive wheel, a shaft journaled for rotation on the sleeve and mounting the abrasive Wheel, the axis of rotation of the abrasive wheel being eccentric with respect to the axis of rotation of the sleeve whereby the axis of the Wheel moves in an orbital path, cam means for reciprocating the abrasive wheel lengthwise of its axis of rotation, supporting means for a drill to be ground, means synchronized with the reciprocatory and orbital movements of the abrasive wheel for rotating the drill supporting means to grind relief regions on the drill, adjusting means for said cam means including a second rotatable shaft, a toothed member movable lengthwise of the second shaft upon rotation of the second shaft, a gear meshing with the teeth of said member and movable with said cam means for adjusting the cam means by rotation of the second shaft, and visual indicating means for determining the position of adjustment of the cam means.

7. Apparatus for grinding twist drills in combination, a support, a rotatable sleeve journaled on the support, a grinding wheel, a shaft extending within the sleeve and journaled for rotation thereon, said shaft supporting the grinding wheel, means for rotating the grinding wheel and sleeve at different rates of speed, the axis of rotation of the grinding wheel being eccentric with respect to the axis of rotation of the sleeve whereby the axis of the grinding wheel moves in an orbital path under the influence of rotation of said sleeve, cam means for reciprocating the grinding wheel lengthwise of its axis of rotation, a rotatable chuck adapted to mount a fluted drill to be ground, an adjustable carriage mounted on said support, a supplemental frame supporting the rotatable chuck, said supplemental frame being pivotally supported on said carriage, a vertically arranged shaft disposed in alignment with the pivotal axis of the supplemental frame, means for driving said vertical shaft, and power transmission mechanism between said vertical shaft and said chuck for driving said chuck.

8. Apparatus :for grinding twist drills in combination, a support, a rotatable sleeve journaled on the support, a grinding wheel, a shaft extending within the sleeve and journaled for rotation thereon, said shaft supporting the grinding wheel, means for rotating the grinding wheel and sleeve at different rates of speed, the axis of rotation of the grinding wheel being eccentric With respect to the axis of rotation of the sleeve whereby the axis of the grinding wheel moves in an orbital path under the influence of rotation of said sleeve, cam means for reciprocating the grinding wheel lengthwise of its axis of rotation, a rotatable chuck adapted to mount a fluted drill to the ground, a carriage mounted on said support and slidable in a direction parallel with the axis of the grinding Wheel supporting shaft, a supplemental frame supporting the rotatable chuck, said supplemental frame being pivotally supported on said carriage for angular adjustment relative to the carriage, a stub shaft disposed in alignment with the pivotal axis of the carriage, means including gearing between said stub shaft and said chuck for driving the chuck, an intermediate shaft for driving the stub shaft, and means for driving said intermediate shaft at different speeds to grind relief regions upon drills having different numbers of flutes.

9. Apparatus for grinding twist drills in combination, a support, a rotatable sleeve journaled on the support, a grinding wheel, a shaft extending within the sleeve and journaled for rotation thereon, said shaft supporting the grinding wheel, means for rotating the grinding wheel and sleeve at different rates of speed, the axis of rotation of the grinding wheel being eccentric with respect to the axis of rotation of the sleeve whereby the axis of the grinding wheel moves in an orbital path under the in fluence of rotation of said sleeve, cam means for reciprocating the grinding wheel lengthwise of its axis of rotation, a rotatable chuck adapted to mount a fluted drill to be ground, a carriage mounted on said support and adjustable in a direction parallel with the axis of the grinding wheel supporting shaft, a supplemental frame supporting the rotatable chuck, said supplemental (frame being pivotally supported on said carriage (for movement about a vertical axis, a vertical shaft disposed in align ment with the pivotal axis of the carriage, and means including gearing between said vertical shaft and said chuck for driving said chuck, an intermediate shaft, means for driving the vertical shaft from the intermediate shaft, and adjustable means for driving said intermediate shaft at different speeds to grind relief regions upon drills having different numbers of flutes.

10. Apparatus for grinding twist drills in combination, a support, a rotatable sleeve journaled on the support, a grinding wheel, a shaft extending within the sleeve and journaled for rotation thereon, said shaft supporting the grinding wheel, means for rotating the grinding wheel and sleeve at different rates of speed, the axis of rotation of the grinding wheel being eccentric with respect to the axis of rotation of the sleeve whereby the axis of the grinding wheel moves in an orbital path under the influence of rotation of said sleeve, means for reciprocating the grinding wheel lengthwise of its of rotation, a rotatable chuck adapted to mount a fluted drill to be ground, a carriage adjustably mounted on said support, a supplemental frame supporting the rotatable chuck, said supplemental frame being supported on said carriage for pivotal movement about a vertical axis, a vertical drive shaft disposed in alignment with the pivotal axis of the carriage, power transmission mechanism between the vertical shaft and said chuck for rotating the chuck, an intermediate sh-aft disposed normal to the axis of said vertical shaft, a countershaft journaled upon the support, a plurality of gears mounted on said countershaft, mean for driving the gears, a gear cluster slidably mounted on said intermediate shaft for establishing a drive from the gears on the countershaft to said intermediate shaft, and means for adjusting the position of the gear cluster with respect to the gears on the countershaft to vary the driving ratio between the countershaft and the intermediate shaft dependent upon the number of flutes in the drill to be ground.

11. Apparatus for grinding twist drills in combination, a support, a rotatable sleeve journaled on the support, a grinding wheel, a shaft extending within the sleeve and journaled for rotation thereon, said shaft supporting the grinding wheels, means for rotating the grinding wheel and sleeve at different rates of speed, the axis of rotation of the grinding wheel being eccentric with respect to the axis of rotation of the sleeve whereby the axis of the grinding wheel moves in an orbital path under the influence of rotation of said sleeve, cam means for reciprocating the grinding wheel lengthwise of its axis of rotation, a rotatable chuck adapted to mount a fluted drill to be ground, a carriage sl-idab'ly mounted on said support, a supplemental frame supporting the rotatable chuck, said supplemental frame being supported on said carriage for pivotal movement about a vertical axis, a vertical drive shaft disposed in alignment with the pivotal axis of the carriage, power transmission gearing between the vertical shaft and said chuck for rotating the chuck, an intermediate shaft disposed normal to the axis of said vertical shaft, a countershaft journaled upon the support, a plurality of gears mounted on said countershaft, means for driving the gears, a gear cluster slid-ably mounted on said intermediate shaft for establishing a drive from the gears 19 20 on the countershaft to said intermediate shaft, and rack References Cited in the file of this patent and pinion means for adjusting the position of the gear UNITED STATES PATENTS cluster with respect to the gears on the countershaft to 24 vary the driving ratio between the countershaft and the 2 Q35 33: intermediate shaft dependent upon the number of flutes 5 2:641:O92 Garrison HULLLHL" him 1953 in the drill to be ground. 

5. APPARATUS FOR GRINDING TWIST DRILLS IN COMBINATION, A SUPPORT, A ROTATABLE SLEEVE JOURNALED ON THE SUPPORT, AN ABRASIVE WHEEL, A SHAFT JOURNALED FOR ROTATION ON THE SLEEVE AND MOUNTING THE ABRASIVE WHEEL, THE AXIS OF ROTATION OF THE ABRASIVE WHEEL BEING ECCENTRIC WITH RESPECT TO THE AXIS OF ROTATION OF THE SLEEVE WHEREBY THE AXIS OF THE WHEEL MOVES IN AN ORBITAL PATH, CAM MEANS FOR RECIPROCATING THE ABRASIVE WHEEL LENGTHWISE OF ITS AXIS OF ROTATION, SUPPORTING MEANS FOR A DRILL TO BE GROUND, MEANS SYNCHRONIZED WITH THE RECIPROCATORY AND ORBITAL MOVEMENTS OF THE ABRASIVE WHEEL FOR ROTATING THE DRILL SUPPORTING MEANS TO GRIND RELIEF REGIONS ON THE DRILL, ADJUSTING MEANS FOR SAID CAM MEANS INCLUDING A SECOND ROTATABLE SHAFT, AND GEARING OPERATED BY ROTATION OF SAID SECOND SHAFT FOR ADJUSTING SAID CAM MEANS. 